allen



E. B. ALLEN.

GIMP THREAD GUIDING MEANS FOR BUTTONHOLE SEWING MACHINES.

APPLICATION FILED MAR20,1920.

1,372,474. Patented Mar. 22, 1921.

INVENTOR WITNESSES: J

E. B. ALLEN.

GIMP THREAD GUIDING MEANS FOR BUTTONHOLE SEWING MACHINES.

APPLICATION FILED MAR, 20. 1920.

1,372,474, Patented Mar. 22, 1921.

3 SHEETS-SHEET 2.

M Q INVENTOR W ATTORNEY Nolms PEYEIS. Inc, LITNO WASMINGT D C.

E. B. ALLEN.

GIMP THREAD GUIDING MEANS FOR BUTTONHOLE SEWING MACHINES.

APPLICATION FILED MAR. 20. 1920.

1,372,474, Patented Mar. 22, 1921.

3 SHEETS SHEEIII INVENTOR ATTORNEY NORRIS PETERS INc LIYHOH WASHINGION D C UNITED STATES EDWARD B. ALLEN, 0F NEWTOWN. CONNECTICUT. ASSIGNOR TO THE SINGER MANUFAC- PATENT OFFICE.

TUBING COMPANY, OF ELIZABETH. NEW JERSEY A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Mar. 22, 1921.

Application filed March 20, 1920. Serial No. 367,298.

To (171 whom if may concern Be it known that I, EDWARD B. ALLEN, a citizen of the United States. residing at Newtown. in the county of Fairfield and State of Connecticut. have invented certain new and useful Improvements in Gimp- Thread-Guiding Means for Buttonhole- Scwing Machines, of which the following is a specification. reference being had therein to the accompanying drawings.

In sewing a buttonhole. it is customary to lay a filler cord or so-called gimp-thread around the buttonhole and cover it with the overseaming stitches. Heretofore, as illustrated for example in my Patent No. 1.278.817 of September 17. 1918. it has been eustomaryto lead the gimp-thread to the sewing point by passing it through a tubular element arranged within and centrally of the usual rotary turret for the lower stitchforming instrumentalities. A lower sewing thread is also passed through this tubular element and. to keep the gimp and lower sewing threads from becoming entangled. it was found desirable to employ a separate tube within said tubular element for the lower sewing thread.

The provision of these separate tubes complicates the construction and increases the cost of manufacture. It also necessitates the use of a large axial aperture within the turret. thereby tending to weaken the construction. Furthermore, it is difficult to lead the gimp thread from the upper end of the tubular element to the usual needlethroat while keeping it out of the range of action of the various moving parts of the stitch-forming mechanism mounted on the turret.

The present invention has for an object to provide a buttonhole sewing machine with simplified and improved means for guiding the cord or gimp from the source of supply to the sewing point while keeping the cord separated from the lower thread and out of the way of the lower stitch-torming instrumentalities.

In accordance with the present improvement, the gimp is guided externally of the turret to the sewing point. thus entirely removing it from proximity to the lower sewing thread and enabling the hollow turret spindle to be made smaller in diameter and stronger and with a single thread-duct within it. As the turret of the the machine is preferably turned through a complete revolution in sewing around a buttonhole and is then rerersely turned to restore it to initial positlol). a gimp-thread guide is mounted on the frame of the machine in proximity to the turret and at an angular position substantially midway between the extreme angular positions of the turret. The purpose ot this arrangement is to enable the gimpthread given up by the turret during the first half of the sewing cycle to compensate for that required by the turret in turning through the second half of the sewing cycle. whereby no strain will be imposed upon the gimp-thread due to the turnin movement of the turret.

in the accompanying drawings Figure l is a fragmentary side elevation of a buttonliole sewing machine embodying the invention. F ig. 2 is a front end view, partly in section. Figs. 3, *Li and 5 are plan views of the lower rotary turret of the machine showing the gimp-thread handling mechanism and the lead of the gimp-thread at the beginning. intermediate and final stages of a buitonholisewing operation. and Fig. 6 is an elevation of the rotary turret and parts carried thereby, looking in the direction of the arrow. Fig. 1.

In the preferred embodiment of the invention. as illustrated. 1 represents the hollow rectangular machine bed from which rises the bracket arm standard 2 for the usual superstructure including the reciprocating eyeminted needle 3 mounted upon and ecccntrically to the needle-bar 4 which. n addition to its reciprocating movements. is turned about its axis in sewing around a buttonhole.

Cooperating with the upper needle 3 is a lower curved and eye-pointed needle 5 fixed in the needle-carrier 6 which oscillates upon the pin 7 at the upper end of the lower needle-supporting post 8 rising from the lower rotary turret 9 having a hollow stem 10 which is journaled within the fixed curb or casing 11. Cooperating with the upper and lower needles is the usual looper 12 which seizes a loop of thread from the upper needle below the work and presents it for entry by the lower needle which, in turn. carries a loop of its own thread up through the buttonhole slit and presents it above the work for entry by the upper needle on its next descent. Stitch-forming mechanism of the above type is well known and is dis closed for example in my Patent No. 1,162,207 of November 30, 1915. As the specific character of the stitch forming mechanism is immaterial to the present invention a further detailed description thereof is deemed unnecessary.

It will be understood by those skilled in the art that the needles 3 and 5 operate through the e .remities of the Ushaped aperture 13 in the usual needle-throat or button 14 which is mounted upon the post 15, Figs. 2 and 6, rising from the turret 9. The extremity of the U-shaped needle apex: ture 13 which receives the lower or curved needle is concentric with the center 0 which represents the axis about which the turret The upper needle 3 is oilset from too the needle-bar which is coincident with the axis 0; the r l operating through the other e3; U-sliaped aperture. The necc motions are imh-lorming instrumentalities by means of the usual tnbu r acti ating rod 16 which reciproc cally w min the hoilow Spllitll 1 turret. The actuatin J the rod 16 and the lUwQl stitch-forming instrumentahties are fully disclosed 1a. my

said Patent No. 1,162.;21' and as they are well known to those skilled in. the art, a d.e-

tailed description thereo't is believed to be unnecessary.

Mounted upon. the post is a gimpthread tension device and guice comprising a plate 17 formed with a thread-eye 1S and threading slit 19. Secured to the inner face of the plate 17 by means of the screw 20 is the lower end of a light leaf-spring 21 the upper or free end of which bears lightly against the inner face of the plate 17 above the thread-eye 18. Also mounted upon the post 15 is one end 01? a slack gimpthread controlling spring 22 the free end of which is bent to form a thread-eye through which the gimp passes on its way from the check-spring 21 to the needle throat 14. A circular guard ring 24 is mounted horizontally upon the curb or casing 11 for the turret 9. This guard ring 24 also assists in guiding the gimp.

The machine is provided with the usual work-clamp 25 and buttonhole cutter levers 26, 27 together with the necessary actuating means which may be and are preferably constructed substantially in accordance with the disclosure of my said patents. A gimp thread pull-oil device 28 constructed substantially in accordance with the dis closure of my said Patent No. 1,27 8,817 is fitted to the side of the machine frame and is operated by the usual cutter-shaft 29.

In the embodiment oi the invention illustrated the post 15 which supports the needlethroat 14 is pivotally mounted. at 15 upon the turret in order that the needle-throat may be tilted forwardly to permit the cutter-levers to move forwardly and cut the buttonhole in stitching position. Mechanism of this type is fully disclosed in my latcnts Nos. 1,048,786 and 1,162,207 and is well known to those skilled in the art. When the needle-throat is tilted forwardly to clear the cutters, the spring 22 yields the necessary slack gimp-thread. This slack is subsequently taken up or absorbed by said spring when the needle-throat is restored to sewing position.

The card or gimp-thread passes from the supply through the pull-off 28, thenc forwardly to the guide 30 which is mounted within the front end oi? the hollow-base 1. From the guide 30 the gimp-thread passes upwardly over the guard ring 24 and through the threadcyes 18 and 23 to the usual gimp-thread guiding aperture in the needle-throat 14.

Referring to Fig. 3, which represents the turret in initial position, it will be noted that a ii :1 0 -i :1 is drawn from the center of rotation of the turret through the guideeye 18.

Another line 0. 2 is drawn from the center of rotation through the stationary guide 30. The line 0-c represents one extreme angular position of the turret relative to the line 0i') and will be seen, in the present embodiment of the invention, to be spaced substantially 180 from the lin 0 The arrow represents the direction in which the turret will move when the stitching operation is started As shown in Fig. the slack.

In Fig. 4 the turret is shown in a position 0a substantially midway between its extreme positions. in this position oi? the turret the gimpthread is slack and hangs loosely over the guard ring 24. The supporting post 8 for the curved needle serves as a guard to prevent the gimp from being drawn into the paths oi' the moving parts, particularly during movement of the turret from the osition shown in Fig. 4 to that shown in *ig. 5.

In Fig. 5, the turret is shown in finalextreme position 0-a. at the end of the stitching operation, having, in the embodiment of the invention illustrated, made one complete revolution. From this position the turret is customarily turned in the reverse direction, as indicated by the arrow, Fig. 5, to restore it to initial position, Fig. 3. r guard 31, secured to the guard ring 24, assists in holding the gimp-thread away from moving parts of the machine.

Having thus set forth the nature, what I claim herein is 1. A buttonhole sewing machine having, in combination, overseaming stitch-forming gimp g is substantially free from v mechanism including up er and lower stitch-forming instrumenta ities, supporting means therefor including a lower rotar turret, and means for guiding a gimp-thread externally of said rotary turret and delivering it at the under side of the work within the range of action of the stitch-forming instrumentalities.

2. A buttonhole sewing machine having, in combination, overseaming stitch-forming mechanism including upper and lower thread-carrying implements, supporting means therefor including a lower rotary turret, means within said turret for guidin a lower sewing thread to the stitch-formlng implements, and means external to said turret for guiding a gimp-thread to and delivering it at the under side of the work within the range of action of the stitchforming implements.

3. A buttonhole sewing machine having, in combination, overseaming stitch-forming mechanism including upper and lower stitch -forming instrumentalities, supporting means therefor including a lower rotary turret formed with a hollow stem, and means for guiding a gimp-thread externally of the stem of said rotary turret and delivering it at the under side of the work within the range of action of the stitchforming instrumentalities.

4. A buttonhole sewing machine having, in combination, overseammg stitch-forming mechanism including upper and lower stitch-forming instrumentalities, supporting means therefor including a lower rotary turret adapted to be turned on its axis through a definite arc in sewing around a buttonhole and to be reversely turned to initial position after the buttonhole has been stitched, means for guiding a gimp-thread externally of said rotary turret and delivering it at the under side of the work within the range of action of the stitch-forming instrumentalities, and a second gimp-thread guide mounted on the frame at an angular position substantially midway between the extreme angular positions of the turret.

5. A buttonhole sewing machine having, in combination, overseammg stitch-forming mechanism including upper and lower stitch forming instrumentalities, supporting means therefor including a lower rotary turret adapted to be turned on its axis through a definite arc in sewing around a buttonhole and to be reversely turned to initial position after the buttonhole has been stitched, and means for guiding a gimpthread externally of said rotary turret and delivering it within the range of action of the stitchforming instrumentalities, said means including a gimp-thread guide mounted on said turret and a second gimpthread guide mounted on the frame at an angular position substantially midway between the extreme angular positions of the movable gimp-thread guide relative to the axis of said turret.

6. A buttonhole sewing machine having, in combination, stitch-forming mechanism including, upper and lower stitch-forming instrumentalities, supporting means therefor including a lower rotary turret, a tiltin needle-throat mounted on said turret and formed with a gimp-thread guiding aperture, and guiding means for leading the gimp-thread externally of said turret to said aperture, said guiding means including a gimp-thread tension device and slack-thread controller mounted on said turret.

7. A buttonhole sewin machine having, in combination, overseammg stitch-forming mechanism including upper and lower stitch forming instrumentalities, supporting means therefor including a. lower rotary turret. and means for guiding a gimpthread externally of said rotary turret and delivering it within the range of action of the stitch forming instrumentalities, said guiding means including a guide below the turret and a guard-ring partially embracing the turret and over which the gimpthread passes to the sewing point.

In testimony whereof, I have signed my name to this specification.

EDWARD B. ALLEN. 

